The present invention relates generally to computer controlled railroad locomotive brake equipment and more specifically to providing redundancy.
The availability of computer controlled railroad brake equipment includes the CCB equipment available from New York Air Brake Corporation. The CCB locomotive brake control equipment is described in U.S. Pat. No. 5,172,316 and is illustrated in FIGS. 1 and 2. The numbers used throughout this application correspond to that used in this patent for sake of clarity and consistency. With computerized and electric control, the operation of the locomotive and the train must be safe for failure of any electrically controlled portion. In the previously mentioned patent, the triple valve 93 in FIG. 7 in combination with the tow cut-out 92, provided back-up pneumatic control of the brake cylinder for the locomotive. With respect to the brake pipe illustrated in FIG. 6 of the subject patent, no pneumatic control was provided for the brake pipe 40.
Thus, it is the object of the present invention to provide further redundancy including control of the brake pipe.
These and other objects are achieved in a brake control unit having a brake cylinder valve, equalization reservoir valve, brake signal valve and brake back-up valve in combination with the controller for selectively connecting a primary signal from the brake signal valve or a back-up brake signal from the back-up brake signal valve to the brake cylinder valve and for selectively controlling the equalization reservoir with the equalization reservoir valve or the primary brake signal. The controller includes a first electropneumatic valve connecting the primary brake signal from the brake signal valve or the back-up brake signal from the back-up brake valve and a second electropneumatic valve connecting the equalization reservoir with the equalization reservoir valve or the primary brake signal from brake signal valve. A first pressure transducer connected to the output of the brake signal valve is used to control the pressure of the primary brake signal or the equalization reservoir. A second pressure transducer is connected to the output of the equalization reservoir valve and is used to control the pressure of the equalization reservoir when the equalization reservoir valve is used to control the equalization reservoir.
Preferably, the controller includes a local brake signal controller for controlling the brake signal valve and the first electromagnetic valve and being connected to the first transducer. It also includes a local equalization reservoir controller for controlling the equalization reservoir valve and the second electromagnetic valve and being connected to the second transducer. A third transducer connected to the brake cylinder is also connected to the local brake signal controller. A fourth pressure transducer connected to the brake pipe is also connected to the local brake signal controller. The controller may also include a local brake pipe controller for controlling the brake pipe valve and a fifth pressure transducer connected to the brake pipe and the local brake pipe controller.
In addition to a brake pipe vent valve, which vents the brake pipe for emergency conditions, being activated by a pneumatic emergency signal from the control stand and from a first electropneumatic valve operated in responsive to the brake pipe transducer by the local brake pipe controller, the brake pipe vent valve is activated by a pneumatic signal from a second electropneumatic valve operated in response to a control signal from a central controller. The central controller affects brake pipe venting redundancy to the brake pipe local controller and emergency signals from an operator.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.